This invention relates to a decorative string set comprised of a plurality of incandescent lamps which plug into complementary sockets along the string set. More particularly, the invention relates to a Christmas tree string set having means which clamp the connection of the lamps to their complementary sockets.
In the past, a variety of constructions have been used to electrically interconnect, in a serial manner, the incandescent lamps of decorative string sets. One such construction is disclosed in U.S. Pat. No. 4,241,387 of H. J. Bowers, which is assigned to the same assignee as the present invention.
A major problem inherent with a serially connected decorative string set is that if any one of the incandescent lamps becomes loosened or removed from their complementary electrical sockets during handling or use, the serial connection is interrupted and the string set becomes inoperative. Loosening of one or more lamps during use is especially troublesome for sets used outdoors, because the effects of wind and vibration can more easily cause the lamps to loosen. While lamps can be secured in their sockets by many different methods, such as by using a metal screw thread base for the lamp, the manufacturing costs for doing such securing are very critical, since the decorative string set product is meant to be produced and sold on a very cost competitive basis. It is desired that a relatively simple means for positive lamp retention or clamping the electrical connection of the lamps to the string set be provided.
A desired feature for the decorative string set that may be used in both indoors and outdoors, are attachments formed into the string set itself and serving as branch clips. These branch clips provide the means for a stationary position of the string set by affixing to the tree located indoor or outdoors. It is desired that the string set be provided with such branch clips but in a relatively inexpensive manner. Further, it is desired that these branch clips be incorporated into the clamping means so as to provide both functions in a relatively inexpensive manner.
In view of the foregoing, it is therefore an object of the present invention to provide a string set having means for positive retention or clamping the electrical connection of the lamps to their complementary electric sockets.
Another object of the present invention is to provide a string set having branch clips which are formed as an integral part of the clamping means.
A further object of the present invention is to provide the clamping means, and the branch clips incorporated into the clamping means, in a manner so as to minimize the cost of the fabrication of the string set itself.